Isolation type power conversion method based on demagnetization iteration control and power conversion circuit

Abstract

Disclosed are an isolation type power conversion method based on demagnetization iteration control and a power conversion circuit. The power conversion circuit comprises a high-frequency transformer, wherein a primary side of the high-frequency transformer is electrically connected with a primary side power tube in a power switch tube circuit, a secondary side of the high-frequency transformer is electrically connected with a charging capacitor circuit and an output feedback circuit through a secondary side synchronous rectifier tube, and the primary side and the secondary side of the high-frequency transformer are electrically connected with a power conversion integrated control chip. The present invention provides a novel demagnetization time iteration loop control architecture, which controls the switching of the primary side power tube by iteratively calculating the demagnetization time, and the method eliminates the right-half-plane zero of a flyback isolation power supply, increases the loop bandwidth and improves the response speed of the system. The influence of signal noise interference during high-speed dynamic response is eliminated through a ripple injection method, and a voltage adaptive turn-on time control technology is adopted, so that a primary side current sampling resistor is omitted, the system cost is reduced, and the system reliability is improved.